Author Topic: Cold idle stalling, need some advice plz. (Read 4631 times)

richbarn2 · « **on:** November 15, 2009, 10:59:09 AM »

Havent been on much since I joined, to be honest I only drive when its raining/snowing or just too cold. I usually ride as much as possible. I just changed my spark plugs (NGK 2 prong), oil, air filter and fuel filter (damn was that thing huge!) none of which has solved my problem. I also rerigged my throttle cable as there was a bit of slop but no such luck.

When I first fire it up in the morning, I have to sit there and open the throttle to keep it running. If I dont the idle drops very low and it sounds like its only running on 3 or possibly 2 cylinders, then it will die. If I keep the rpm's about 1500 until I see some coolant temp indicated, it will idle normally.

After its warmed up and been driving for a while it runs pretty well. It will idle around 800, rather steady, but it does wander a bit from time to time and I can occasionally feel a slight miss during idle, but Im not expecting it to be perfectly smooth. I did notice a surging in 1rst gear just above idle speed in a parking lot recently, I had to actually disengage the clutch and rev it a bit to clear it? TPS?

My fuel mileage has slowly decreased from the low to mid 30's to barely 30 usually high 20's. Oh, its a 95 318IS with 150,000 miles. I was thinking a new 02 sensor and cleaning my idle control valve next, any help would be greatly appreciated.

Rich

carlos318is · « **Reply #1 on:** November 15, 2009, 03:05:16 PM »

Sounds like its the idel control valve mate cuz that is what happens to my other halfs E36 give it a clean and should be good

richbarn2 · « **Reply #2 on:** November 15, 2009, 03:33:05 PM »

I'll try that this week for sure. Thanks for the reply. I was reading a thread on bimmerforums that suggested replacing the coolant sensor also, its 20 bucks and I'm pretty sure its never been changed. From what I have read, it seems to do similar things when it fails...

Ill replace the coolant sensor and clean the idle contol valve and post my results. Thanks again...

carlos318is · « **Reply #3 on:** November 15, 2009, 04:09:28 PM »

No probs mate

richbarn2 · « **Reply #4 on:** December 03, 2009, 04:09:11 PM »

I had my Snap On dealer read my codes tonite. Turns out the airflow sensor is flagged. According to his BMW tech buddy via phone call during the check, he said the airflow sensor should be at 4 at idle. mine was in the teens... Bummer. IIRC they are expensive.

The 02 was flagged as well but the tech said to start with airflow sensor as it will affect the o2 signal. Also the values for the o2 sensor were not that far off, guess thats why he suggested the airflow sensor first, then go from there...

Anybody have one for sale?

1991 E30 M42 · « **Reply #5 on:** December 03, 2009, 05:16:40 PM »

Shoot a PM to Jimmy Lewis, I think ha has a nice spare that he would be willing to part with.

DesktopDave · « **Reply #6 on:** December 03, 2009, 05:51:59 PM »

Don't replace the MAF before you do the ICV. I'd go after this problem from cheap to expensive. I'd be wondering if the intake temp sensor was bad. It's integrated in the MAF but I've heard of guys replacing it for only a few bucks. Can't hurt to check it!

I had a similar problem with mine, though no O2 code. I had a resistor harness installed on the AFM (I think it was an e30-only deal). The AFM connectors were waterlogged & shorted the signal. DME told me bad AFM with a 1215 error. AFM was fine, ICV was fine, just had to remove the resistor pack harness & dry out the connector.

richbarn2 · « **Reply #7 on:** December 03, 2009, 06:47:54 PM »

Quote from: 1991 E30 M42;82451

Shoot a PM to Jimmy Lewis, I think ha has a nice spare that he would be willing to part with.

Thanks man

Quote from: DesktopDave;82456

Don't replace the MAF before you do the ICV. I'd go after this problem from cheap to expensive. I'd be wondering if the intake temp sensor was bad. It's integrated in the MAF but I've heard of guys replacing it for only a few bucks. Can't hurt to check it!

I had a similar problem with mine, though no O2 code. I had a resistor harness installed on the AFM (I think it was an e30-only deal). The AFM connectors were waterlogged & shorted the signal. DME told me bad AFM with a 1215 error. AFM was fine, ICV was fine, just had to remove the resistor pack harness & dry out the connector.

I was going to change my temp sensor. I definitely will change it, and all of the vac hoses and clean the ICV and airflow sensor next.

Im pretty sure its not a water problem, I have inspected my connectors. All looks well there...

Is there a resistance check I can do on the airflow meter to exclude the other sensors that are associated with it?

richbarn2 · « **Reply #8 on:** December 13, 2009, 11:01:55 PM »

I found a barely used Python MAF, much cheaper than the remanufactured factory MAF on pelican. I see that Python is an aftermarket unit and is rated as poor on pelican. Any thoughts?

richbarn2 · « **Reply #9 on:** December 23, 2009, 06:36:45 AM »

Boy do I feel dumb. It took the cold weather to for me to notice the enormous crack in my intake bellows. I taped it up as a temp fix until my new one arrives. Completely solved my cold idle problem and surging in first gear. Figures, I just bought a serviceable Bosch AFM on ebay. Im going to install it and see if my fuel mileage changes, if not I have a good spare. I may even sell it if someone needs it.

I also ordered a K&N air filter, temp sensor and O2 sensor with my new intake bellows from Pelican. Even after the AFM purchase and my Pelican purchase, I am several hundred dollars under what I expected. I think I'll splurge and get some new headlights from DDM with the leftover funds and possibly a new water pump and FDM kit from understeer.